The intent of this research project is to ascertain the relationship between Vitamin A and Lung Cancer. This study is being carried on in Louisiana, a state known to have very high incidence of lung cancer. Preliminary analysis of available data (National Nutrition Survey and HANES) indicates a negative correlation between beta-carotene (precursor of Vitamin A) and mortality rates due to respiratory system cancers and also with mortality from all neoplasms, but not with total deaths. We have also initiated case control studies in which dietary intakes and Vitamin A concentration in hepatic tissue of patients who died of lung cancer will be compared with appropriate controls. Studies have also been started in living patients suffering from lung cancer. Serum level concentrations and dietary intakes of Vitamin A are measured and compared with those from matched controls. The information to be obtained from these studies would provide evidence for the suggested relationship between Vitamin A (and/or other nutritional factors) and lung cancer.